Composition for lining can ends



Patented Sept. 10, 1935 s'm'rss v Z,l3,67

COMPOSITION FOR LINING CAN ENDS John E. Robinson, Glen Ellyn, Ill.,assignor to American Can Company, New York, N. Y., a corporation of NewJersey N Drawing. Application December 31, 1926, Serial No. 158,414

9 Claims.

This invention relates to compounds for lining can ends and the like,and has for its object broadly the provision of a compound liningmaterial which may be readily dried in the can end to form a thoroughlysatisfactory liner or gasket material of shortened characteristics, ascontradistinguished from the elastic characteristics, of the rubbercompounds generally in use prior to this invention. This application isa continua- 10 tion in part of co-pending application Serial No.

9,512, filed February 16, 1925.

A highly important object is the elimination of benzol and otherinjurious solvents now generally employed in the compounds used for thelining of can ends and the like.

The invention contemplates in this regard the use of no solvent exceptWater and the use of this in such fashion as to be practical and permitof thorough drying with simple drying equipment within reasonable time.

The commercial rubber compound in the past has required the use ofbenzol or other solvents dangerous to health and of inflammablecharacter, as solvent for the rubber which constituted the principalingredient of the compound. Ef-

fort has been made to use latex for the lining of can ends but it hasbeen found to be of too elastic character and of other undesirablequalities and difiicult of application to the can end itself, even whenapplied in a concentrated form, As an example of its undesirablecharacteristics, it may be mentioned that the lining produced from thelatex has been found to absorb hot water and squeeze out of the seam inthe double seaming operation.

In accordance with the present invention, a body of relatively inert andinelastic character is incorporated with the latex and a material isadded to hold the body material, which is in finely divided insolublecondition, in proper dispersion in the liquid compound before drying inthe can end. The dispersal agent is or may be a colloid adapted todistribute or disperse the filler uniformly throughout the latex andmaintain it in suspension. The dispersal agent or colloid preferably,although not necessarily, is of a character to produce the desiredviscosity in the liquid compound prior to its application to the canends and preferably, although not necessarily also,

5Q it is of a water-proofing character. An example of a suitable colloidis an alginate, as for example ammonium alginate, although othercolloids adapted to accomplish the desired dispersion and suspension ofthe filler are contemplated.

55 A preferred composition embodying the invention has been found toresult from the use of calcined aluminum oxide as the body material anda product of alginic acid as the dispersing or dispersal agent. Thealginic compound is an ammonium alginate, which does not combine readily5 with the aluminum oxide and which acts as a. colloid to coat thecalcined aluminum oxide particles to prevent conversion of the latexinto irreversible rubber. An excess of ammonia is used to preventpremature coagulation of the latex and 10 to maintain the alginate inits desired original condition throughout mixing, handling, andapplication to the can end.

A preferred and workable formula results from the use of two pounds ofaluminum oxide; two 15 pounds of alginate emulsified wax solution, andtwo pounds of latex. The strengths of the solutions of the alginate andthe latex are determined by the consistency desired and a slight excessof ammonia is maintained. The compound is pre- 20 pared by thoroughlymixing the alginates and the aluminum oxide in a ball mill or grinderand then adding and mixing in the latex. As the mixing operationsproceed ammonia is added to maintain proper concentration of ammonia.The al- 25 ginate is preferably fortified by the addition of a suitablefortifying agent, for example, a suitable amount of a wax, as beeswax,which is first saponified with ammonia and then mixed into the ammoniumalginate. A formula for the alginate 30 emulsified wax solution is asfollows:

Water 80% Solids 20% :Emulsified beeswax 60 Ammonium alginate "40% 35 Itis thought that the invention and many of its attendant advantages willbe understood from the foregoing description, and it will be apparentthat various changes may be made in the matter of the ingredients, theiridentity and their pro- 40 portions without departing from the spiritand scope of the invention or sacrificing all of its materialadvantages, the form hereinbefore described being merely a preferredembodiment thereof. 45

I claim:

1. A compound for lining can ends and the like, comprising a solid bodymaterial, a solution of latex and fortified ammonium alginate.

2. A compound for lining can ends and the like, comprising a suitablemetal oxide, latex, and fortified ammonium alginate.

3. A compound for lining can ends and the like, comprising aluminumoxide, latex, and fortified ammonium alginate.

4. A compound for lining can ends and the like, consisting of a solidbody material, a solution of comprising a body material, latex, analkali allatex, and a fortified alkali alginate. ginate and fortified bysaponified wax. 8. A composition for lining can ends and the 5. Acompound for lining can ends and the like, like, consisting of a mixtureof an alkali alginate,

5 comprising a body material, latex, an alkali algisaponified Wax, afiller, and latex. 5

nate and saponified wax. 9. A composition, consisting of an alginic ma-6. Acompound for lining can ends and the like, terial, saponified wax,latex, and an inert maconsisting of a solid body material, a solution ofterial. latex, and a fortified algin salt. o 7. A compound for liningcan ends and the like, JOHN E. ROBINSON. 10

